High speed fluidic devices

ABSTRACT

This invention relates to a binary accumulator stage consisting of pure fluid bistable and OR-NOR elements. The stage is joined with other similar stages to form a binary accumulator. Each stage sums an input value, a carry-in value supplied by a previous stage, and an addend value present in the addend register. An output signal and a carry-out signal are generated by each stage, the carry-out signal being fed to the succeeding stage as a carry-in signal.

t d tslf ent 9 I 9' 82 J 9 ichards-6061.1 y.-, 1 1 i4si ii1 23,-1974HIGH-SPEED FLUIDIC DEVICES [75] Inventors: Edward F. Richards; Warren B.Y

- Depperman, both of Winterpark,

OTHER PUBLICATIONS Fabrication Techniques, Fluid Amplifier State of theArt, General Electric Co., Schenectady, N.Y., Vol.

['73] Assignee: Martin-Marietta Corporation, New [Langley et al.,Modular Pneumatic Logic Package,"

York, NY. f v v IBM Technical Disclosure Bulletin, Vol. 6, No. 3, Oc-{221 Filed? 16! 1970 I. tober 1963,10- 3-.4. g [2 PP ,9 Y 1Priritary"EacamineP-Lawrence R. Franklin Related Application Data 1gomgy, Agent, or FirmJulian C. Renfro, Esq.; Gay [62] Division Of'SCT.N0. 546,935, May 2, 1966, Pat. No.

' r g e [57] ABSTRACT "I in ntion relate's.to' a accumulator tage [5.1]Int. e G06d 1/10 Econsisting of pure fluid bistable and ORNOR 1 [58]Field of r 235/201 PF; 1137/ 's ments. The stage'is joined with othersimilar stages to form a binary accumulator. Each stage sums an input 1Rsfmnces Cited value, a carry-in value supplied by a previous stage, 1 1UNITEDSTATES PATENTS I and an addend value present in the addendregister. 3,182,676 5/1965 Bauer ..'..l iii/ 1.5 An tp t signal and ay-out ig a are generated "3,-l90,554 6/1965 G'ehring et al.

v 235/201 PF by each stage, the carry-out signal being fed to the3,226,023 1965. Horton... 235/201 PF succeeding stage as a carry-insignal. 3,286,086 11/1966 Bauer .3235/20-1 PF 3,350,009 10/1967 Rose235/201 PF 1 g 1 7 Clams, 13 Drawing Flgllms .Aoozuo] f I, sum toeicCARFRIYFLOGI'C PAIENTED 3.825.739

I saw '2 or a FIG. 2

PATENTEDJUL23l974 SHEEI 3 OF 8 OUTPUT CARRY OUT CARRY LOGIC ADDEND LOGICFIG. 4

ADD SHIFT RESET INPUT ARY CUMULATOR GE PICAL OUTIPUT 2 2 2 2| g I l a5\34 as -3 1 QARRY OUT ADDW SHIFT:

RESET:

I I l FIG. 3

PAIENTEnmzamu 325.139

SHEET 5 OF 8 FIG. 7

PAIENTED M2 3.825.739 sum 70F a FIG. IO

FIG. ll

' HIGHSPEED FLUIDIC-DEVICES This is a division of application Ser. No.546,935,v

filed May 2, 1966, now US. Pat. No. 3,550,604.

computation, and control. We intend also that this'term willernbracesuch systems and devices presently known as pure fluid systemsanddevices, fluid amplifiers, fluid transistors, fluid power systemsandfluid jet systems and devices; t I

'In the past'a'number of so-called pure fluid devices have beenproposed, but these have been characterized by their relatively largesize and slow operating rates,

and for-these and other reasons, such prior art fluid devices werenotsuit'able for complex logic applications.

These earlier devices have typically involved utilizing a'stream offluid under pressure, and at leasttwo receivers, into one or the otherof which receivers the stream of fluid can be caused to flow, withcontrol meansrbeing positioned so as to deflect such stream into thedesired receiver. Such devices have been the subject of numerouspatentsand many publications,

.with their proposed uses by industry becoming larger each'successiveyear. Howevenall known prior art devices of this type are either analogdevices or digital Coanda effect-devices, and their operating rates havebeenvery muchslower than thecomparable electronic devices. As a result,itqhas not heretofore been feasible. to perform the. complex functionsnormally associated with electronic logic by the use of fluidic devices.

As isknown, a network of logic elements for sequencing, computing andcontrol system applications must complete a data cycle within the timeinterval defined by the intended use. Therefore, thenumber' of logicelements that can be effectively utilized in a given applicationdependsupon the operatingrate. in other words, the number of logic elementsdefines the numerical accuracy and functional capability of the digitaldevice, so therefore the operating rate of logic elements is of vitalimportance in that it establishes directly the capabilityof the digital.mechanization. lt-is known that in a fluid device, the operating rateis directly related to size, and although the velocity of propagationvby fluid signals is limited, by employing very small element ite adeqate response times can be obtained.

Whereasprior art fluid logic devices have been large and slow, suitableonly for primitive logic networks, we

have dramatically extended the utility of the fluid logic technology bymaking our logic elements small and fast acting, so'as to make themhighly useful incomplex logic devices.

a turbulent flow that substantial entrainment. of ,ad- I jacent-fluidcan occur, but advantageously, the laminar flow emanating from ournozzle is caused to turn to turbulent flow before the confines of thecavity are passed,

which means that a desirable entrainment of the fluid from the cavitycan take place, thus reducing the pressure therein andholding the jet offluid in'the desired position. e

More specifically, our novel'concept makes possible .a new class ofminiaturized fluid logic devices that significantly'can operate oninitially laminar jets.

In our elements, the novel interaction area geometry is used to inducedesired bistable or monostable ope ratio'n without dependence onsidewall attachment. In this class of device, miniaturized sizes can beem.- ployed, where laminar power jets are encountered.

Laminar power jets interact with boundary fluid I through viscous forcesonly, so there is no appreciable momentum exchange. As a result, thereisi'nsuffrcient entrainment of fluid as is necessary to develop anadequate pressure gradient by proximity to a sidewall.

However, the necessary pressure gradient is established in thisclass byinternal feedback, and/or selectively inducing turbulence in a portionof the jet.

In other words, our novel concept makes possible a new class ofminiaturized fluid logic devices that can operate on initially laminarjets, and the fact that turbulent nozzle flow is precluded in smallsizes due to the high ratio of surface to cross section in smallchannels is overcome by virtue of the fact that our novel cavity-configuration desirably induces turbulence in the initially. laminarjet at a location close to the nozzle exit.

Several other desirable effects are also'brought about, with the netresult being 'to provide fluid logic devices in a smallness of sizeheretofore considered impractical. The aforementioned cavity is.disposed between the control-port and a receiver, whichcavity includesan upstream edge and a downstreamedge. The relationship of the upstreamedge with respect to the jet is such that the control cavityis in effectisolated from the control port except when switching'pressure is appliedthereto. That is to say, when the jet is flowing past the upstream anddownstream edges, the cavity portion of the chamber is in effectisolated, with the entrainment of fluid being such that a negativepressure is created in the cavity, which lowered pressure causes the jetto stay in the selected position. i

Upon the arrival of the control signal at the control port, this causesthe jet to move away from the upstream edge or point, thus to allow flowto take place from the control port into the previously evacuatedcavity; This of course serves to dissipate the lowered pressure thereinandthereby to cause the jet to tend to move away from the'cavity.Switching thereafter takes place very rapidly, such as within20-microseconds.

By-virtue of the fact that we can'achieve highly satisfactoryperformance with only a very small supply nozzle, such as a nozzle of awidth dimension of 0.004 inch,

We have created a new fluid element configuration I utilizing a novelcavity past which a jet of fluid from a nozzle can'flow. Because .of theunusual properties of this cavity configuration, laminar nozzle-flow canbe used and the device made much smaller than was ever previouslypossible. As is known, it is only by virtue of tional advantages, suchas the fact that each logic plane it is possible'for us to resort toprinted circuit tech niques in the creation of our elements, and toemploy copper foils that are 0.004 inch thick. As will therefore beseen, our nozzles are 0.004 inch on a side, .or have an aspect ratioof 1. This is of course to be contrasted with the smallest nozzleheretofore known, which was some 0.014 deep and 0.008 wide.

Our small nozzle makes possible a number of addi- 3 can be very thin andthereby make possible the stacking of dozens or even hundreds of logicplanes into a single logic device. Whereas the aforementioned prior artnozzle that was 0.014 deep could be made by the use of say seven foilsof 2-mil stock, we can make selfcontained logic planes that are each0.004 inch thick, utilizing a single foil thickness for each logicplane, thus of course circumventing the alignment and registrationproblems that accompany devices whose elements are made of a pluralityof layers.

It is significant to note that the application of a control signal tothe control port brings about switching of the jet to the other receiverin a very rapid manner by v virtue of the fact that the distance fromthe control port to a receiver can be very short. This is to becontrasted with the prior art configurations, in which the nozzle wasthought to be necessarily large in order to obtain the initiallyturbulent flow required in fluidic elements.

Accordingly, it is a principal object of this invention to provideminiature high speed fluid logic elements that can be quite successfullyemployed in sophisticated, yet very small logic networks. Further, sincethe operating rate in accordance with our invention allows the use of alarge number of elements in a given size package, it is another objectof this invention to provide high density element packages and fluidlogic that can be produced at very low cost.

A further objectof this invention is to provide fluid logic elementswith practical circuit characteristics such as adequate fan-in, fan-outcapability, low power consumption, and reliable operation over a widerange of supply pressuresand loading characteristics.

Our invention provides a substantial improvement over Coanda effectdevices in that through the use of our novel control cavityconfiguration, initial turbulence in the fluid jet is manifestly notnecessary.-Our

cavity enhances stability of the fluid jet with respect to the selectedreceiver in a most significant manner, and because wall attachment isnot required, our logic device is operable over a wide range of supplypressures. This is to be contrasted with Coanda effect device, whoseattachment point undesirably varies with supply pressure aswell as otherinputparameters.

As will therefore beseen, in a fluidic device in accordance with ourinvention, a source is employed'from which a fluid jet issues, andcontrol port means are provided for switching the fluid jet between'oneor the other of two alternative receivers. Asearlier men-- tioned, meansdefine a novelcontrol cavity between the control port means and areceiver, which cavity serves to generate a low pressure with respect tothe jet so as to hold same in a stable position with respect to therespective receiver. This cavity includes an upstream edge contactedby-the jet in such a manner that the control cavity is isolated from thecontrolports except when switching pressure is applied thereto.Switching pressure applied at the control port serves to move the fluidjet away from such upstream edge and produce a comparatively highpressure within the cavity so as to effect a switching of the jet to theother receiver in a very short time, such as in 20 microseconds.

to hold the fluid jet in a stable position with respect to a selectedreceiver can be utilized in a number of configurations, such as one inwhich a pair of cavities is used in symmetrical fashion, with eachcavity being associated with one of two receivers, thus to form afluidic flip-flop device or a pulse relay. As an alternative, however, asingle cavity can be used to form a fluidic OR-NOR logic gate, forexample.

In each of these instances it will be noted that the use of our novelcavity concept for developing the pressure gradient that holds the fluidjet in a selected position amounts to a substantial improvement over theprior art devices wherein a wall was employed for holding the jet in theselected position. This is of course because a high operating ratesimply cannot be obtained in the large sizes required by wall attachmenttype devices. Further, by virtue of the fact that in accordance withthis invention no wall is used to which the jet is to attach, switchingcan be brought about in an extremely rapid manner by merely causing thejet to move away from a cavity-defining position. It should be notedthat our so-called wall-less concept possesses quite accept- .ablestability standards inasmuch as low pressure is developed in even asingle cavity tending to hold the stream of fluid in the desiredlocation. When a pair of cavities is used, the cavity opposite the jetin any in- .stance serves to increase the fluid pressure on the jet andthus operates with the low pressure to hold the jet in the desiredposition.

These and other objects, features, and advantages will be more apparentfrom a study of the drawings in which:

FIG. 1 is a perspective type view of a logic device in accordance withour invention, illustrating the logic matrix in conjunction with top andbottom manifold plates secured in position;

-FIG. 2 is an exploded view of several logic circuit planes of the typeused in the logic device of FIG. I, with the interconnecting fluidpassages between elements. being indicated;

FIG. 3 is a block diagram of an exemplary fluid circuit in accordancewith this invention, in this instance of description;

FIG. 7 represents a device along the lines of FIG. 6 but possessing theconfiguration of a fluidic flip-flop, presented to a scale much largerthan that of the actual device;

FIG. 8 is a perspective view of the device shown in FIG. 6;

FIG59 is a perspective view of the device shown in FIG. 7;

FIG. 10 represents a single-cavity version of our novel concept, thisparticular device being a fluidic OR-NOR logic gate;

FIG. 11 is another symmetrical cavity arrangement in accordance with ourinvention, this device being in the form of a load-controlled fluidicpulse relay;

FIG. 12 is a perspective view of the device shown in FIG, 10; and

FIG. .13isa perspective viewof the device shown in FIG. 11.. I l I V vlogic matrix in accordance with this invention may Referring to FIG. 1,logic device 10 is there depicted, I

' comprises a comparatively large number of logic circuit planes whichtogether form the logic of this device. In this instance, the device isa six-bit binary accumulator,such as could be an integral building blockof a digital computing mechanism. A similar assembly could contain logicfora sequencer or other digital control device. i

As will be apparent from FIG. 1, the INPUTS or augend 14 as well as thefluid power source 15 are disposed in bottom manifold plate 11, with theOUTPUTS 16 as well as the sequencing control ports'17, 18 and 19 beingdisposed in the top manifold plate 12. All of these inputs and outputscould be provided by-controllable (manually or automatically) interfacedevices or could be a consequence of othersignals where this device actsas a subassembly of a more complex digital mechanization,

The fluid power source 15 is a continuous pressure with a flow capacityadequate for the device, with prescomprise dozens or even hundreds oflogic planes, with it also being understood that the five planes shownherein are typical planes that maybe juxtaposed in the illustratedrelation in apre-established location in a typical logic device. Eachcircuit plane is preferably surized gases such as, for example, air,nitrogen, or the like being usable.

- The INPUT 14 is so configured as to allow a series of fluid pressuresapplied as a binary coded number. For example, the number 3 could beapplied at the INPUT 14 by pressurizing the 2 and 2 ports, with zeropressure simultaneously being maintained at the- 2 2 2,

and 2 ports. Similarly, the number l5 could be applied to the INPUT 14by pressurizing the 2, 2, 2 and 2 ports, with no pressure applied at the2 and 2 control ports. I i

The top manifold plate 12 contains the ADD control port 17, SHIFTcontrol port 18, and RESET control port 19, as mentioned earlier, whichports are used to sequence the logic device- Here momentary pressurepulses areselectively applied which control the logic operations. On theside of the top manifold plate, the OUTPUT set 16 is located, with thisset servingto transmit the result of the logic device operation to areadout or. to a subsequent similar logic device. In other words, thisoutput can be used in controlling and/or sequencing mechanisms orapplied to another similar logic device to perform a more complexcomputing function. Each port of theOUTPUTset 16 is selectivelypressurized as a consequence of the logic device operation, and as anexample, this output set could represent a binary coded number. Forinstance, the number 29 would be presented by having pressure at 2, 22*,and 2, with zero pressure at ports 2 and 2 i The hole 21 in themiddle of the top manifold plate extends down .through'thelogic matrixto provide a chamber which is used for venting the internal logicdevices. The outer boundaries of the logic matrix are similarly used tovent the logic devices, such as to the atmosphere or a lowpressureplenum.

Turning to FIG. 2, it will be noted that in this exploded view of atypical fluidic logic assembly in'accordance with our invention consistsof five exemplary circuit planes I through V containing our novel logicelements and their interconnections, arrayed in the approximaterelationship. that they are disposed in the logic matrix. It is ofcourse to be understood that the made of copper foil, because of thecomparative ease with which known etching techniques may be employedtocrea'te logic elements in accordance with this inventionfAlso, copperfoils are preferred from the standpoint of manufacture, for a desirednumber of foils may be satisfactorily secured together in apreestablished relationship either by clamping, screwing, or suitablebonding techniques. However, it is within the contemplation of ourinvention to use foils of brass, copper-brass alloy, or even stainlesssteel if such be desired, withthese of course being used in thethickness desired.

As will be apparent, each logic plane is prepared in accordance with apre-established standard and basic'ally involves the use of three typesof interconnections; power supplies, vents, and signal passages, with italso being evident that several logic elements may be disposed in eachlogic plane. These elements will be discussed in detail hereinafter, andit should at this point suffice to say that the elements used on theplanes 'of FIG. 2 are either flip-flops of the type appearing in FIGS. 7and 9, orelse OR-NOR gates of the type appearing in FIGS. 10 and 12..Theelement configurations are designed so that the metal foil after etchingdoes not fall apart. This is made possible by the fact that steppingbetween elements often takes place between two or more adjacent planes,with the arrange- 35 ment being such that appropriate communicationamong the elements is conveniently made possible. As will also beapparent, the logic pattern in each instance'is arranged circularlyaround the common vent 21 to facilitate simultaneous venting on theinside as well as on the outside of the stack. Power supply ports -22through 27 are disposed adjacent the elements, or

perhaps more accurately, the elements are disposed in such a manner asto partake of the fluidpressure available at power supplyports. Forexample, elements P &

Q are disposed in Plane 1 connected to ports 22 and 23,

element R is disposed in Plane II connected to port 26, etc. The powersupply ports will be noted to continue through all five illustratedplanes. As will be understood, the Fluid Power Source 15 of FIG. 1 isconnected to the supply ports'by appropriate power supplyinterconnections and passages disposed in bottom manifold plate 11, andin a similar manner, the input ports, output ports and control ports areconnected to the matrix 13 formed of the standardized circuit planes bymeans of other appropriate passages disposed in the manifold plates. Bystandardized it is meant inthis context that the power supply ports, thecentral vent, and the indexing holes are in a pre-established location,and that the material size is the same.

FIG. 2 also reveals how fluid logic elements can be interconnected incomplex sequencing and computing circuits. Each of the logic elementsemployed in this matrix must operate at a high enough rate so that thecomposite speed of the complete logic device is suitable for theintended application. In addition, a number i of the logic elements mustbe capable of farming out to a multiplicity of other elements andsimultaneously.

being controlled by a fan-in from a multiplicity of elements.Interconnections among logic elements can be made either in a horizontalplane or by transferring vertically from stack to stack, the decision ineach instance largely dependingon good design practice. Since as isapparent, at large number of discrete digital logic elements is requiredto mechanize digital devices in most practical applications, thisimposes a requirement in addition to the other characteristics of thelogic circuits, which is that they must be suitable for low costfabrication techniques such as by certain photo etch processes.

Our invention will be explained by next referring to FIG. 3, which is ablock diagram of a logic device, in this example a six-bit binaryaccumulator employing stages 31 through 36. As indicated earlier andshown here, the input to this device is a binary coded set, and thethree controls, ADD, SHIFT and RESET, are used to sequence itsoperation. Similarly, the output is another binary coded set. Associatedwith each binary bit there are'blocks containing the CARRY LOGIC, theSUM LOGIC and the ADDEND LOGIC, as indicated in FIG. 4. In this example,the binary input set is added in a parallel fashion to the existingbinary coded num ber on the ADDEND LOGIC and the result transferred tothe SUM LOGIC. Whenever necessary as the consequence of the additionoperation, digital logic is employed'to transmit a carry to the nexthigher ordered bit. This-addition operation is controlled by amomentary' removal of the fluid signal tothe ADD control channel. Thisbinary coded set is then transmitted and- /or displayed at the OUTPUTports.

To prepare the device fo the next add operation, the binary coded numberof the SUM LOGIC is transferred to the ADDEND, is this instance bymomentary removal of the pressure signal at the SHIFT control port. In,this case, element of the SUM LOGIC, and elements P, Q and R of theADDEND LOGIC cooperate to perform the function of a shift register,where the state of the first bistable element 0 is shifted to the secondbistable element R without changing the condition of element 0. Theresult of this automatic, or manually applied sequence of ADD and SHIFTcommands is to accumulatively add thebinary codednumber applied as theINPUT set. The INPUT set can of course be changed-at any time, as forexample from a bina'ry'function generator or an interface associatedwith the application of this device. v

The RESET control port can be used-atinitiation of the operation and/orintermittently to reset each bit of the device to zero. The OUTPUT iscontinuously presented and presents the binary number existing at anypoint in time in the SUM LOGIC.

Turning now to FIG. 5, this is a schematic of the logic ineach bit ofthe accumulator. Element 0 is the SUM flip-flop, element 0 the OUTPUTflip flop, and element R is the ADDEND flip-flop. Element R' of courseappeared in FIG. 2, and the precise operation of this result on element0 and O, and transmitting a CARRY (and the other) bistable devices willbe set forth in connection with FIGS. 7 and 9. Similarly, the OR-NORelements of FIGS. 2 and 5 will be discussed in detail in connection withFIGS. 10 and 12. It should be noted from FIG. 5 that removal of theSHIFT signal to the control ports of OR-NOR elements P and Q results inthe transfer of the state of element 0 to element R. Similarly, removalof an ADD signal to the control ports of OR-NOR elements M and N resultsin adding the ADDEND, CARRY IN, and INPUT, displayingthe OUT throughelement F as required. Monostable elements A through G of FIG. 5represent the CARRY LOGIC, elements H through 0 the SUM LOGIC, andelements P through T the ADDEND LOGIC.

In the device shown in FIG. I, assume that signals are normally presentat the ADD CONTROL PORT 17 and the SHIFT CONTROL PORT 18, and that boththe ADDEND LOGIC and SUM LOGIC of FIG. 5 have been reset to O. In thisinitially assumed condition, all OUTPUT signals 16 will be zero. Nowassume that an INPUT signal 14 is applied to the first bit or the 2INPUT port.

In order to add this number, which represents 1 in this case, to thenumber in the ADDEND LOGIC, which is now 0, one must momentarily removethe ADD control signal at port 17. This process sets the elements O andO in the SUM LOGIC in the first bit to the 1 channel which indicates 2or 1. The signal to the ADD control port 17 is then reapplied and thenumber I in the SUM LOGIC of the first bit is then shifted to the ADDENDLOGIC of the first bit. This is accomplished-by momentarily removing theSHIFT control signal 1 8 which sets the ADDEND flip-flop R of the firstbit from the 0 channel to the 1 channel. This in conjunction with the 2input set signal generates a CARRY OUT signal from bit 1 which isapplied to bit 2 as a CARRY IN. The second add operation will then addthe number existing in the ADDEND LOGIC, in this case 2 or 1, to thenumber existing in the INPUT, again in this case 2 or 1. This isaccomplished by again momentarily interrupting the signal at the ADDcontrol port which results in setting the elements 0 and O in the SUMLOGIC of the second bit from the 0 channel to the 1 channel, andsimultaneously setting elements 0 and O of the SUM LOGIC of the firstbit from the 1 channel back to the 0 channel. This results in changingthe condition of the OUTPUT signals 16 from a 2 state to a 2 state. Thisis equivalent to saying that the sum of 2 2 =2 or 2.

The exact mechanics of how this is accomplished may be seen by referringto FIG. 5 and it is described in the following discussion.

In this situation assumed for the purpose of explanation, let FIG. 5represent the second bit of the 6 bit binary accumulator. Because allinput signals except the 2 signal are absent, the input to bit 2 will bein the 0 state, thus explaining the 0 at the INPUT near the bottom ofFIG. 5. As a result of the first addition and shift, a CARRY OUT wasgenerated from bit 1, thus explaining the 1 condition existing here atthe CARRY IN of bit 2. The ADDEND flip-flop R of bit 2 was previouslyset to the 0 channel by the initial premise of the problem. Now, inorder to explain how the second addition process sums these threesignals, the INPUT 0, the CARRY IN 1, and the ADDEND 0 to provide a 2OUTPUT, the following discussion is presented.

As previously indicated, it is to be realized that the arrangement ofOR-NOR gates and bistable elements shown in FIG. 5 represents one bit ofan exemplary logic device designed to receive, shift and add binarylogic signals. Each element of FIG. 5 is connected to the fluid powersource 15 of FIG. 1 and each element is designed to perform a discretelogic function in a manner described in detail hereinafter. As will beapparent, the control ports of monostable logic elements A andB receivethe CARRY IN signals and the control I port of monostable element G. g

. SHIFT pulses supplied through port 18 of FIG. 1 are i ports ofelementsC and Bare designed toreceive the INPUT signalfThe control portof elementgD is designed to receive the output from the receivers ofelements A and C when the control ports of latter elements are receivingno signaland such elements are therefore inthe on condition. Similarly,the outputs of elements DI: and B. are directed to the control ports ofelements E and -F,*respectively, as well as to the control directed tothe control ports of elements P and-Q of the ADDENDILOGIC of FIG. 5,with these elements also on occasion receivinginputs on lines 51 and 52from bistable element O, the presence of a signal on a given linedepending of course upon the state of latter element. ADD pulsessuppliedto port 17 of FIG. 1 are reelements aredirectly responsible forswitching bistable element 0. One of the outputs of related bistableelement represents the OUTPUT 16.

Asearlier mentioned, the CARRY INto the CARRY LOGIC is' from the CARRYOUT from the preceding stage, and conversely the CARRY OUT depicted inFIG. 5 becomes the CARRY IN of the succeeding stage. 7 An. input,present in the .CARRY LOGIC can be transferred to the OUTPUT 16 bymeans of operating the SHIFTand'ADD control signalsthrough ports 18 and17 of FIG. 1. It should be noted that a change in the state of the CARRYLOGIC can be brought about without affecting the state of the output.Operating the vice are performed in binary logic fashiomand proviso thatthen state" 6r; element I will bedecided by the state of element T ofthe ADDEND LOGIC.

Assuming element T ison, element J is turned off and therefore no signalwill exist on line 66, thus allowing the state of element K-to dependupon the state of element 11. Since element 11 was turnedoff by elementG, there will be no signal in channel 72 to element K, so element K willbe on and therefore element L will be off. Assuming no pressure isprovid'ed at this moment by the ADD input port, element M'will be on andwill provide a signal in line 68 to the control port of bistable"element 0, causing it to have an output in thel channel ceived by acontrol port of elements M and N, which port of element Q. Since elementK is now on, element N is off, thereby allowing element 0 as justmentioned to provide a signal on line 52 that will turn" element Q off.The signal and thereby provide a signal on line 52 to the control online 68 further flips element 0 to the OUTPUT 16 SHIFT and ADD inputcontrol signals, the new input .will be added to the "quantity alreadypresent in the SUM LOGIC block, All the logic functions in this de--.

sions are made to. carry the necessary-signals to the next bit of thedevice.

Referring to the by control port 14,0f FIG. 1 to either a lora 0, and asjust reiterated, the CARRY IN represents the I or T the 0 CARRY OUT fromthepr evious bit. In thisexample, the-INPUT is a 0, so element C is inthe on position, and a pressure signal flows through line 40 to acontrol port of monostable element D. This of course causes a switchingof element D to the off condition during the continuation of thepressure signal, thus preventing at this time the transmission of asignal to the control ports of elements E and G. I In this case-,a l ispresent in the. CARRY lN,.and this turns off element A, but this isirrelevant in this instance insofar as element Dis concerned, forwhether or not there is a signalfrom A to element D on line 41 will notchange the'state of element D when as here it has already been switchedto the'off position by the sig nal from C. -:f' t

CARRY Loorc; the INPUT is set positionlAs will be seen, we haveperformed the binary addition of three signals, the, ADDEND a 0, the

CARRY IN a Land the INPUT a 0, with the result j being a 1. Sincethiswas assumed to be the second binary bit .in the system, this 1appears at the OUTPUT 16 as a signal to the 2 output. This OUTPUTrepresents the value 2, which is the sum of the INPUT 2 or 1, and thevalue that was in theSUM LOGIC, also a 2 tion one must momentarilyinterrupt the SHIFT control signal 18, whichessentially transfersthenumber exist- "ing at the-OUTPUT'16 of the SUM LOGIC into the The CARRYIN signal is also senton line 42 to'a con 'trol port of element B andturns it-off, thus' in this instance making the presence of anINPUT atthe control port of element B irrelevant.

As will now be apparent 0 (zero) signals exist on lines 43 and as aresult of B and D being in the off condition, so element G'will be inthe on positionand will provide a pressure signal on line 64 to thecontrol ports of elements 11 and I of theSUM LOGIC, turning them off.Since element I is nowoff, there will be no signal on line 65 connectedto the control port of element J,

ADDEND LOGIC. This is accomplished by'the AD- DEND LOGIC block of FIG. 4which involves elements.

B through T of FIG. 5.. I v

.In orderto actually seehow this is accomplished in thephysical circuit,refer back to'the exploded view of FIG. 2, which-is relatable to aportion of FIG. 5. Since the output ofbit 2isnowin the l channelastheresult of the previous operation, a signal will be present on line52,which appears in plane I of FIG. 2 as well as in FIG. 5. This of courseis a control input to monostable element O which holds this element inthe off condition or 0 state. A shift control is normally present inchannel 53, and as seen-in plane II, this channel branches into channels54 and 55(not shown in FIG. 5 Channels 54 and 55 intersect channels56and 57, respectively, with these latter channels being control inputs toelements P and Q respectively. As long as the shift control signal ispresent, both, of thelatter. elements will be held in the off condition.However, when .the shift pulse is interrupted, element P will turn onsince as was noted, no

signal is present in line 51 from the zero channel of element 0. Element0, however, will remain off because of the signal that is present inchannel 52. When ele-" ment P turnson, its output is appliedthroughlogic plane II into channel 58 of logic plane III and back to channel 59of logic plane II, which is the control port of bistable element R OFlatter plane. This sets element R tothe channel 1 condition. Sinceelement R is a bistable element, it will remain in this condition 'even7 11. y when the signal from channel 59 is terminated. This signal isterminatedby'reapplication of the shift" pulse,

which again'turns element P off. Element R has now been switched to the1 channel and the signal from the l channelis transferred through logicplane III to logic plane IV, where via line 71 it feeds the control portof element T. Contemporaneously, since element R was switched from thechannel to the 1 channel, the signal in the 0 channel was removed, whichremoves the sig- 5 to be carried out. For example, a total of say logicin line 51 to element P and that the signal in channel 52 has thereforebeen removed. This results when ele ment 0, due to successive additionprocesses, has been switched from the 1 channel back to the 0 channel.

. Now, when the shift control signal is terminated, element P willremain off due to the signal in channel 51, but element 0 will turn onsince the signal in channel 52 is no longer present. When this occurs,the output from element Q travels through logic plane II, throughchannel 60 of logic plane III, back up to channel 61 of logic plane II,back down to channel 62 of logic plane Ill, and up to channel 63'oflogic plane II, which is a control port of element R. This switcheselement R from the 1 channel back to the 0 channel and causes acorresponding change of state of the remaining ele ments driven byelement R. Again, when the shift control signal is reapplied, element Rwill now remain in the 0 channel since it is bistable, even thoughtheshift control signal again turns off element O. This completes thedetailed discussion of FIG. 2.

Under the initially-assumed conditions, element F was not generatingaCARRY OUT. I-Iowever,.when R is flipped t0 the b As will be apparentfrom this exemplary circuit, element F will provide a l at the CARRY OUTif any two of the CARRY IN, INPUT, or ADDEND LOGIC represent a- 1.However, if only one, or none, of these isa 1, then element F is off,and a 0 is provided;

The foregoing description of a typical logic mechanization was presentedin order to illustrate the way in which our novel fluidic elements canbe employed in complex'integrated fluidic circuits. By using our novelelements in a counter circuit in which simple interconnections werepossible, a packaging density of approximately 500 elements per cubicinch .was" obtained, whereas in a computer circuit made in accordancewith these principles, a number of interconnecting planes in the natureof Plane III of FIG. 2 were required, and the packaging density fell to200 elements per cubic inch.

As will be apparent to those skilled in the art, by effective design,certain logic devices have packaging densities of 1,000 fluidic logicelements per cubic inch or even higher can be built. As a result of theuse of our principles, substantial improvement in overall operat-' ingrate can be effected relative to existing fluidic techniques.

Turning now to a detailed description of our novel fluid elementconfigurations, and referring to FIGS. 6 and 7, it will be noted thatnozzle is designed to provide a stream of fluid or jet that flows from asuitable source into control chamber 81, which chamber is principallydefined by arcuate sidewalls 82 and 83. The dimension of the channelassociated with source 80 can be quite small, such as 0.004 inch wide.As will be more apparent hereinafter, these sidewalls 82 and 83 ineffect define cavities 84 and 85 that serve in a highly advantageousmanner to hold the stream of fluid from 80 flowing into receiver 86 orreceiver 87, the particular receiver depending upon the direction of themost recent signal received in the control section 88 of the device.

' As will be noted, the cavities 84 and 85 are of welldefinedconfiguration, which start from a lower edge or point adjacent thecontrol section 88. This is upstream edge or point 90 in the case ofcavity 84, and upstream edge or point 91 in the case of cavity 85. It ismost significant to note that when the stream of fluid from source 80 isflowing into receiver 86, for example, the stream flows closely adjacentupstream edge 90 whereas when the flow offluid is into receiver 87, thestream of fluid flows closely adjacent upstream edge 91. As will beobvious from the configuration exemplified in the figures of drawingshown herein, when the stream of fluid is closely adjacent a point oredge, the respective cavity is in effect isolated from the rest of thechamber, and most significantly such cavity is isolated from the controlport area. At such times as the jet flows closely adjacent one of thesewell-defined cavities, a comparatively low pressure is developedtherein, as will be described more fully hereinafter, thus holding thejet in a desired position and eliminating the need for utilization ofthe Coanda wall attachment phenomena, as inprior art devices.

Control parts 92 and 93 are provided on opposite sides of the device asshown in FIG. 1 and arranged to open into the control section 88 of thedevice. A proper signal at control port 92 will be sufficient to rapidlyswitch the stream of fluid or jet from receiver 86 over to receiver87,-and conversely, a proper signal at port 93 will be sufficient torapidly switch the jet from receiver 87 over to receiver 86. ExemplaryFIG. 6 therefore represents a form of fluidic flip-flop.

Referring to FIG. 7 wherein a typical flow configuration is illustrated,it is to be understood that a lowpressure region is created in one orthe other of the well-defined cavities 84 or 85 as a result ofentrainment of cavity fluid by the jet when it is adjacent a particularcavity. The jet, which is initially laminar, seals off the cavity atupstream edge 90 or 91 as well as the respective downstream edge94 or 95so that a small amount of entrainment creates a substantial decrease inpressure that is suitable for holding the jet very stably in thatposition. In this figure, the flow is into receiver 87, and two smallarrows indicate the flow of fluid from cavity 85 as a result of thisentrainment.

The cavities are also employed to quickly induce turbulence in aninitially laminar jet. This is necessary since laminar jets do notentrain fluid effectively enough to create the desired low-pressureregion in the cavity. The transition to turbulence is effected by aninitial disturbance from the respective upstream edge,

in this instance. edge 91,

13 transverse fluid interactions during flow acrosscavity 85,,andthesonic reflections from the respective downstream edge, in this instanceedge 95. These effects combine to induce turbulence in the initiallylaminar jet at a point betweenthe upstream and downstream edges of thecavity, as illustrated, and it is the turbulent portion of the jet thatentrains fluid from cavity 85 to create a low-pressure region in theportion of the chamber defined by the arcuate wall 83 and the stream offluid when such stream is adjacent this cavity. In other words, when thejet or stream '18 on the right hand side of the chamber as viewed'inFIG. 7, it seals off the cavity 85 and thus isolates this low pressureregion fromjthe control section 88 of the device. This advantageouslyprevents dilution of this low pressure region by flow through thecontrol port and enhances the stability of the element as well as eliminating undesirable interactions with other elements connected to thecontrol zone by means of attachment to controlports 92 or 93 as the casemay be.

It should be noted that the stability of the jet that is achieved as aresult of the low pressure created in cavity 85 when the stream of fluidis disposed on the righthand side of the chamber is not derived entirelyby virtue of cavity 85, fora desirable high-pressure regionis created onthe opposite side of the stream of fluid as a result of the feedbackflow injector 96 operating in conjunction with opposite cavity84. Theimmediately foregoing statement is based upon the fact that the feedbackflow injector 96 returns a portion of the power jet along the arcuateupper and side boundaries of chamber 81 to react against the jet inthevicinity of itsupstream edge, as is depicted'by some eight smallarrows in FIG. 7. In addition to thisreaction, the rein jected velocityhead is converted tov static pressure which acts against the entire jetto-help maintain ,iton the selectedside. Thus it will be seen thatwhether the stream of fluid is flowing into receiver 86 or receiver 87,the feedback flow injector 96.will serve in concert with the cavitythatat that instant is farther from the stream'of fluid to create apositivepress'urebuildup serving withthe low pressure created in thecavity neartion switching of the jet over the-receiver 86, this beingaccomplished in 20 microsecondsorso rather than reest the jet to holdsuch stream offluidin the selected position.

It is not to be assumed tion ofhigh and low pressures serving to holdthe stream of fluid in the desired position that switching is difficultto bring about, for in reality the converse is true, switching is quiteeasily'an d very rapidly brought about in accordance with our noveldesign. Significantly, the pressure required to direct the jet from onereceiver to the other issubs'tantially lower than the pressure recoveredin the receiver, which of course detines the gain of'the element andestablishes the fan-out capability of our device. F an-out of courserefers to the;

number of downstream logic elements that can be controlled from'oneelement. Assuming the stream of fluid in the right-hand position asillustrated in the'bistable device depicted in.

FIG. 7, upon-the application of a control pressure at control port 93,such acts on the jet upstream of edge 91 and establishes an initialdeflection. This serves to open a low resistance path between edge 91andthe jet control cavity 85, allowing the control signal to flowrapidly into the low-pressure region and distributing the switchingpressure along the entire span of the ca'vity. The result of this is a"nearly instantaneous snap acthat because of this combina quiring' one ormore milliseconds in. accordance with prior art devices wherein thecontrol pressure had to walk along the length of an attachment wall'inorder to bring about switching of the jet away from that wall to thealternate position. Since the switching control forces act on the jetupstream of the cavity, switching is accomplished in accordance with ourinvention without the necessity of having to overcome the stabilizingforces.

The fluidic flip-flop illustrated in FIG. 7 shouldlbe noted to bear aresemblance to the illustrative device depicted in FIG. 6, but differsin that it utilizes bleed ports or channels 98 and 99 connected to theleft and right receivers 86 and 87, respectively. As will be seen,

' these bleed channels serve to enhance stability of the element withrespect to output impedance changes, increase pressure recovery, permitstableoperation into a blocked load condition, and provide signalisolation in circuit interconnections.

Assuming the jet is entering the right-hand receiver 87 of FIG. 7, 'if,the load impedance of this receiver is increased, pressure would risethroughout the righthand receiver if ableed channel were not present,and

eventually a pressure value would be reachedthat would cause the jet toseparate from downstream edge 95, which would unseal the low-pressureregion existing in cavity 85 and allow receiver pressure to feedbackinto'this region. This of course would serve to raisethe pressureonthe right-hand side of the jet and undesirably cause'switching.

When in accordance with the embodiment shown in FIG. :7 bleed channelsare incorporated, the pressure at point'95 is prevented by channel 99from rising to a level.'-that would cause separation of the jet fromthispoint and the jetremains stable on the right-hand side jacent left-handreceiver 86, a similar advantageous operating' characteristic isobtained when the fluid jet is disposed to flowinto the oppositereceiver.

As another point with respect to this novel configuration, when the jetis flowing into say the right-hand receiver, the bleed channel of theleft-hand receiver acts as a vent for any signals that may be impressedon the left-hand receiver, thus tending to provide a desirable isolationof the high-pressureregion from such signals.

- A similar advantage is also obtained of course when the jet is flowinginto the left-hand receiver, by virtue of the location of the right-handbleed channel. Althoughwe are-not to be limited to certain foilthicknesses, we generally prefer the use of comparatively thin foils, ofa thickness of 0.010 inch or less, and highly satisfactory results havebeen obtained by using 0.004 inch foils. An approximate relationshipbetween foil thickness and preferred cavity size may be deduced fromFIGS. 8 and 9, which of course correspond .to FIGS. 6 and 7respectively. Like FIGS. 6 and 7, FIGS.

trating the chamber relationships, and do not purport to show as FIG. 2somewhat did, the inlet and outlet connections or orifices associatedwith the control ports and the receiver s. These orifices are of courseto be understood to be connected to appropriate channels in the sameplane, or in adjacent planes.

As revealed in FIG. '9, if the nozzle 80 is presumed to be of a widthdimension D,the chamber dimension from the nozzle outlet to the feedbackflow injector 96 maybe timesD, the width of a cavity'in the direction offlow may be 6.5 D, and the depth of the cavity 2 D. These dimensions arequite satisfactory over a wide range of source pressures, but we ofcourse are not to be limited to same, for the chamber configuration canbe varied somewhat if pre-established source pressures are to be used.

Turning now to FIG. 10, we illustrate in detail an OR- NORdevice inaccordance with our invention. In this device, a geometric bias exists,so that an output is provided in NOR receiver 107 at all times exceptwhen a control signalis present. When any combination of one .or morecontrol inputs is applied to the control port 113, the device willswitch so that an OR output is provided in left-hand receiver 106.Therefore, this defice is monostable and can satisfactorily perform theafore v8 and 9 are primarily provided for the purpose of illussion atthe nozzle eXit,-the upstream edge or point 110,

the downstreamedge or point- 114, and thecomplex flow interactions inthe jet control chamber 101 is essentially the same manner as thatdescribed earlier for the symmetrical jet control chamber. Thetransition to turbulent flow is depicted in, FIG. 10.1-lowever, in thisembodiment, the jet is biased, as previously mentioned,

so that it always establishes itself in the right-hand receiver 107 whena control signal is not present. This biasing is accomplished byrotating the power nozzle 100 through a small angle from the centerlineof the device so that it pointslmore towa'rd'the right-hand receiver 107than to receiver 106. The .jet remains 'in this position as a result ofits momentum and the force developed along its left-hand side due to thehigh-pressure region resulting from the action of the feedback flowinjector described earlier. In this case, provision is not made for asealed low-pressure cavity on the right-hand side of the jet since theforces developed by the highpressure region on the left-hand'side of thejet and-the jet's momentum are adequateto normally hold the jet in theright-hand receiver. In this instance, the righthand bleed channel 119serves the same purpose as in the corresponding description of thefluidic flip-flop; it enhances stability of the device with respect tooutput impedance fluctuations, increases pressure recovery, and permitsstable operation into a blocked load. The left-hand bleed channel 118provides isolation from signals that may be impressed on the left-handreceiver 106.

assume, as illustrated, that a signal is applied to the 'control port113. This signal will raise the pressure on mentum and the forceresulting from the high-pressure region on the left-hand side of the jetdue to the feedback flow injector 116, and the jet will switch to theleft-hand receiver 106.

The jet is held in this position by a combination of two forces. Theseare the force resulting from a high pressure region on its right-handside due to the control signal, and a force resulting from a lowpressure region developed in thesealed cavity 104 disposed betweenpoints 110 and 114 located on the left-hand side of the jet. The reasonsfor establishment of this low pressure region were of course discussedin detail earlier.

In this state, the left-hand bleed channel 118 now provides the requiredstability with respect to output impedance variations, resulting inincreased pressure recovery and stable operation with blocked receiveroutputs. Again, the right-hand bleed channel 119 serves to isolate thejet control chamber from spurious signals that may be impressed on therighthand receiver 107. However, in this case, the right-hand bleedchannel serves another very important function. As shown in FIG. 10, thebeginning of channel 119 is located upstream of the tip of the feedbackflow injector 116. This allows the flow from the feedback flow injector116 to be dumped out the right-hand bleed 119 during the illustratedconditions, which prevents establishment of a high-pressure region dueto feedback flow injection on the right-hand side of the jet. Thisenhances return switching to the right-hand receiver when the controlsignal is removed, thereby increasing frequency response.

Another bleed channel, channel 112, is used in this embodiment, and islocated opposite to the control port 113. This channel is-identical tothe left-hand controlport described earlier in the discussion of thefluidic flip-flop. Although it is not used as a control input in theOR-NOR logic gate, channel 112 serves a twovalue. This in turn permitsswitching to the left-hand receiver with a lower magnitude controlsignal than would be the case if this bleed channel were not used.

This feature then provides increased gain and frequency response.

In addition, bleed channel 112 enhances return switching from theleft-hand to the right-hand receiver. To illustrate this, assume the jetis switched to the lefthand receiver and then the control signal isremoved.

As the control signal is removed, the power jet deflects toward theright because of the angle of the nozzle, and breaks-the seal-between itand point 110. This opens the low pressure region 104 on the left-handside of the jetto the bleed channel-112, which provides a source As tothe details of switching the OR-NOR device, I

of flow to fill the low-pressure cavity 104 and raises the pressure inthis cavity to ambient level. This results in easier and more rapidreturn of the jet to the right-hand receiver than if bleed channel 112were not used. This feature also tends to increase frequency response.

As is therefore to be seen, the arcuate cavity 104, in a manneranalogous to that of the bistable device, facillitates the transition toturbulent flow and isolates the resultant low-pressure region from bothdownstream and upstream effects, thus to enhance pressure recovery. Thevery fast response of our device is of course .power source. Also, theoutput'receiver in which the jet is established is controlled by apressure differential applied across the receiver-outputs rather than byconventional control ports. 1

Consider first operation of the device when the nozzle is powered.Assuming the jet is set to the right-hand receiver l 27,=a turbulent jetis developed due to the combinedinfluence .of disturbances that occur atthe nozzle exit, point 131, point 135, and the complex flow interactionsinthe jet control chamber 125 in a manner similar to that describedpreviously. A low-pressure region will be developed on the right-handside of the jet, and a high-pressureregion on its left-hand side. inexactly the same manner as these pressures are developed in the basicjet control chamber. If the jet is established in the left-hand receiver126, the pressure forces acting across itare of course reversed. Therightand lefthand bleed channels 139 and 138 serve the same purpose asthe corresponding bleed channels of the fluidic flip-flop. I v

The unique feature of this embodiment is the manner in which the jet isdirected toward a certain preselected receiver. Consider the-device whenthere is no pressure applied to. the power nozzle, and apply a pressuredifferential across the output receivers withthe pressure applied torightfhand receiver 127 greater than that applied to left-hand receiver126;This pressure differential will establish aflow pattern in thedevice such that 'flowtravels down the right hand receiver, across thejet control chamber from right to left, and up through the left-handreceiver. Of course, some flow also escapes through the vent channels,but asubstantialamount is passed acrossjthe jet control chamber fromright to left.

Now consider what occurs when a pulse'is applied to the power nozzle120. Initially a lowenergy jet begins to issue from nozzle exit and thecirculating flow in the jet control chamber deflectsthis jet to theleft. As the power jet builds in intensity it developsa low-pressureregion in left cavity 124 and a high-pressure region on its right .in amanner described previously, and the forces resulting from thesepressures hold the jet stably in left-hand receiver 126. The jet willremain in this position until the pulse at the power nozzle isterminated. Oncethepowet pulse is terminated, a controlpressure from theload device.during the off portion of the nozzle power pulse.

As is therefore to be seen, we have provided a new, useful andunobviou's contribution to the fluidic art, in the form of 'a fluid jetdevice utilizing elements with 'unique chamber configurations. Atleast'one cavity in accordance with this invention is disposed in suchchamber, between the control port and receiver sections of the element,and by generating low pressure on one side of the fluid jet flowing intoa receiver, and a high pressure on the other side, this novel cavitybrings about the stable maintenance of the jet in a desired position inthe chamber until such time as a control signal is applied to thecontrol portsection.

This inventioncan manifestly be utilized in monostable as well asbistable forms, and makes possible the utilization of elements so smallthat only laminar flows can emanate from the fluid nozzles of theelements.

However, by virtue of thefact that ournovel'cavity plays a vital role inbringing about the turbulent flow desired in the element chamber,elements with comparatively large jet nozzles are not required, thusmaking possible the construction of fluidic devices of a small size notheretofore thought possible, withmuch higher switching speed.

Six or so of such elements may be disposed on a single logic' plane orfoil smaller than one inch on aside, and by the use of appropriateinterconnection and stacking techniques, dozens if not hundreds of suchfoils can be arrayed into a highly versatile device in which elementdensity of several hundred per cubic inch is obtained. i I I Asmentioned earlier, the logic planes are designed to conform to astandard layout. With this layout each logic element is placed in one ofsix orso correspond ing positions in-all planes containing logicelements, so that when these planes-are stacked, a vertical columndifferential can be re-established across the output receivers; Supposethat inthe next case the pressure a'pplied to the left-hand receiver isgreater than that applied to the right-hand re'ceivfenThis willestablish a flowin the jet control chamber'from left to right. When apulse is again applied to the power nozzle, this left-toright flowcirculation will direct the jet to the righthand receiver 127,'where itwill remain until the power pulse is terminated. Therefore, this devicetransmits a power pulse to a particular output receiver, such receiverbeing selected by a pressure. differential supplied of elements iscreated. These columns of elements are arranged in a circular fashionaround a common center vent 21 extending through the central area of thestack, which arrangement permits each column of elements to be poweredfrom a common vertical supply passage formed from aligned ports, 22, 23,24, etc. It also permits short, direct,and properly orientedinterconnections from element column to element column. In addition,element bleed passages on the outside of the element ring'can be porteddirectly to the edge of the stack, while vents on'the inside of theelement ring are ported directly to the center vent. eliminating thecrossing of bleed and signal passages and simplifying circuit design.

As will be understood by those skilled in this art, a given device inaccordance with our invention may involve some degree of repetition ofplane design, and for example, one device of planes used some 40different plane designs constructed to the aforementioned standardlayout principles. However as the device involvedbecomes more complex,there generally is less repetition of plane design in a device.

As will be apparent, by utilizing the aforementioned standardconfiguration principles, several different basic logic planes can bemade in large numbers utilizing certain etching techniques. These logicplanes are typically made of foil as previously mentioned, and becauseeach foil is an inch or less on a side, such logic planes can be made inlarge sheets that are thereafter separated to form the-individual logicplanes. Quite ob- 7 plane contain an element, for as was noted inconnection with logic plane Ill in FIG. 2, some of the planes maycontain only interconnecting passages. Further, not all the logic planesof a given fluidic device need be of the same thickness, for if such bewarranted, thicker or thinner planes than a standard thickness may beincorporated in a given fluidic device. Further, it is not necessarythat the logic planes constituting a fluidic device be bond'ed together,for other techniques such as screwing the planes together may beemployed. Furthermor e the planes need not be metallic material, for insome instances thin planes of dimensionally stable plastic or even glassmay be employed.

With regard to the recovery obtained by our elef ments, we have foundthat a pressure recovery of percent is typical, with better values thanthis being obtained on many occasions. Flow recovery under certainconditions may actually exceed nozzle flow. As to pressure gain, whichmay be defined as recovered pressure divided by the pressure required toswitch the element, values from 5 to 10 can be expected, depending onelement design. Flow gain, as defined in an analogous manner, may alsorange from 5 to 10. These values when multiplied together representpower gain, which therefore may range from 25 to 100.

We claim:

l. A fluidic binary accumulator stage comprising:

a. fluidic means for entering a carry-in signal from a previous stage;

b. fluidic means for enteringan input signal;

0. fluidic carry logic means for summing said input signal and saidcarry-in signal into a first sum and for providing a partial carry-outsignal;

d. a fluidic addend register including a first fluidic memory meanswhich contains an addend value;

e. fluidic sum logic means for summing said first sum and said addendvalue into a second sum;

f. a second fluidic memory means;

g. a fluidic OR-NOR logic circuit means responsive to said second sumfor setting said-second memory means;

b. means to receive an add signal for actuating said OR-NOR logiccircuit means;

i. a feed back circuit from said second memory means to said addendregister for entering said second sum into said first memory means, saidfeedback circuit including fluidic gating means;

j. means to receive a shift signal for actuating said gating means; and

k. a fluidic carry-out logic circuit means responsive to said partialcarry-out signal and an output of said addend register to provide acomplete carry-out signal for a subsequent accumulator stage.

2. A fluidic binary accumulator stage comprising:

a. fluidic means for entering a carry-in signal from a previous stage;

b. fluidic means for entering an input signal;

c. fluidic carry logic means for summing said input signal and saidcarry-in signal into a first sum and for providing a partial carry-outsignal;

d. a fluidic addend register including a first fluidic bistableflip-flop which contains an addend value;

c. fluidic sum logic means for summing said first sum and said addendvalue into a second sum;

g. a fluidic OR-NOR logic circuit means responsive to said second sumfor setting said second bistable flip-flop;

h. means to receive an add signal for actuating said OR-NOR logiccircuit means;

i. afeedback circuit from said second flip-flop to said addend registerfor entering said second sum into said first bistable flip-flop, saidfeedback circuit including fluidic gating means;

j. means to receive a shift signal for actuating said gating means; and

k. a fluidic carry-out logic circuit means responsive to said partialcarry-out signal and an output of said addend register to provide acomplete carry-out signal for a subsequent accumulator stage.

3. A fluidic binary accumulator stage as defined in claim 2 incombination with at least one other accumulator stage of substantiallyidentical construction thereby forming a multi-bit accumulator.

4. A fluidic binary accumulator stage as defined in claim 2, including afluidic output stage coupled to said fluidic OR-NOR circuit means andresponsive to its output.

5. A fluidic binary accumulator stage as defined in claim 4 incombination with at least one other accumulator stage of substantiallyidentical construction thereby forming a multi-bit accumulator.

6.."A fluidic binary accumulator stage as defined in claim 4, whereinsaid fluidic output stage is a third fluthereby forming a multi-bitaccumulator.

1. A fluidic binary accumulator stage comprising: a. fluidic means forentering a carry-in signal from a previous stage; b. fluidic means forentering an input signal; c. fluidic carry logic means for summing saidinput signal and said carry-in signal into a first sum and for providinga partial carry-out signal; d. a fluidic addend register including afirst fluidic memory means which contains an addend value; e. fluidicsum logic means for summing said first sum and said addend value into asecond sum; f. a second fluidic memory means; g. a fluidic OR-NOR logiccircuit means responsive to said second sum for setting said secondmemory means; h. means to receive an add signal for actuating saidOR-NOR logic circuit means; i. a feed back circuit from said secondmemory means to said addend register for entering said second sum intosaid first memory means, said feedback circuit including fluidic gatingmeans; j. means to receive a shift signal for actuating said gatingmeans; and k. a fluidic carry-out logic circuit meanS responsive to saidpartial carry-out signal and an output of said addend register toprovide a complete carry-out signal for a subsequent accumulator stage.2. A fluidic binary accumulator stage comprising: a. fluidic means forentering a carry-in signal from a previous stage; b. fluidic means forentering an input signal; c. fluidic carry logic means for summing saidinput signal and said carry-in signal into a first sum and for providinga partial carry-out signal; d. a fluidic addend register including afirst fluidic bistable flip-flop which contains an addend value; e.fluidic sum logic means for summing said first sum and said addend valueinto a second sum; f. a second fluidic bistable flip-flop; g. a fluidicOR-NOR logic circuit means responsive to said second sum for settingsaid second bistable flip-flop; h. means to receive an add signal foractuating said OR-NOR logic circuit means; i. a feedback circuit fromsaid second flip-flop to said addend register for entering said secondsum into said first bistable flip-flop, said feedback circuit includingfluidic gating means; j. means to receive a shift signal for actuatingsaid gating means; and k. a fluidic carry-out logic circuit meansresponsive to said partial carry-out signal and an output of said addendregister to provide a complete carry-out signal for a subsequentaccumulator stage.
 3. A fluidic binary accumulator stage as defined inclaim 2 in combination with at least one other accumulator stage ofsubstantially identical construction thereby forming a multi-bitaccumulator.
 4. A fluidic binary accumulator stage as defined in claim2, including a fluidic output stage coupled to said fluidic OR-NORcircuit means and responsive to its output.
 5. A fluidic binaryaccumulator stage as defined in claim 4 in combination with at least oneother accumulator stage of substantially identical construction therebyforming a multi-bit accumulator.
 6. A fluidic binary accumulator stageas defined in claim 4, wherein said fluidic output stage is a thirdfluidic bistable flip-flop.
 7. A fluidic binary accumulator stage asdefined in claim 6 in combination with at least one other accumulatorstage of substantially identical construction thereby forming amulti-bit accumulator.